Mufflers for internal combustion engines

Claim 2

An exhaust muffler for an internal combustion engine comprising a housing including a dished outer shell, an outer back plate and an internal separator plate substantially parallel with the back plate to form with said back plate an exhausting chamber and with said outer shell a muffler chamber, a wad of sound absorbing material in one part of the muffler chamber, a perforated sound reflector plate opposite to the wad in another part of the muffler chamber, an inlet and an outlet in the housing for gases exhausted from an exhaust port of the engine, said inlet being sealed from said exhausting chamber and passing through said back plate and said separator plate into said other part of the muffler chamber to direct exhaust gases onto and through said sound reflector plate, said outlet being connected with said exhausting chamber, and means for attaching the muffler housing to the engine with said inlet in communication with said exhaust port.

Claim 3

An exhaust muffler as claimed in claim 1, wherein reinforcing ribs are formed in the separator plate to resist vibration of said plate when in use.

Claim 4

An exhaust muffler for an internal combustion engine provided with an exhaust port, comprising a housing including a dished outer shell, an outer back plate closing an open side of the shell, an internal partitioning separator plate defining together with the back plate an exhausting chamber and together with the outer shell a muffler chamber, a perforated panel between the separator plate and the shell dividing the muffler chamber into two compartments, a wad of sound absorbing material in a first one of said compartments, an inlet for exhaust gases sealed from the exhausting chamber and passing through the back plate and internal separator plate into a second one of said compartments, a reflector plate in the second compartment dividing same into two parts and having an inclined surface in a first of said compartment parts and opposite the inlet to reflect the shock wave component of exhaust gases entering the inlet towards the sound absorbing wad, means for permitting passage of exhaust gases from the inlet through the first part of the second compartment into a second of the said parts thereof and thence into the exhausting chamber, and an outlet for exhaust gases connected with the exhausting chamber.

Claim 5

An exhaust muffler for an internal combustion engine provided with an exhaust port, comprising a housing including a dished outer shell, an outer back plate closing an open side of the shell, an internal partitioning separator plate defining together with the back plate an exhausting chamber and together with the outer shell a muffler chamber, a perforated panel between the separator plate and the shell dividing the muffler chamber into two compartments, a wad of sound absorbing material in a first one of said compartments, an inlet for exhaust gases sealed from the exhausting chamber and passing through the back plate and internal separator plate into a second one of said compartments, a reflector plate in the second compartment dividing same into two parts and having an inclined surface in a first of said compartment parts and opposite the inlet to reflect the shock wave component of exhaust gases entering the inlet towards the sound absorbing wad, means for permitting passage of exhaust gases from the inlet through the first part of the second compartment into a second of the said parts thereof and thence into the exhausting chamber, and an outlet for exhaust gases connected with the exhausting chamber.

Claim 6

An exhaust muffler as claimed in clAim 3, wherein a peripheral marginal edge area of said outer shell, back plate and separator plate are clamped together in a peripheral folded joint.

Claim 7

An exhaust muffler as claimed in claim 4, wherein the marginal edge area of said back plate is folded around the marginal edge areas of the separator plate and the outer shell, and the marginal edge area of the separator plate is set angularly away from the plane of said separator plate to effect an interference condition in the resulting seam.

Claim 8

An exhaust muffler as claimed in claim 3, wherein the muffler is generally rectangular and said outlet is located near one end of the muffler and directed in a direction substantially normal to that at which the inlet is directed.

Claim 9

An exhaust muffler as claimed in claim 3, wherein the inlet is an aperture in an annular dished seat for an annular sealing gasket adapted to accept an exhaust port spigot from the engine, said muffler comprising spring clips for holding the housing to the engine with the spigot forced onto the sealing gasket on the seat.